Vice President Joe Biden holds pizza boxes after traveling to Catanzaros Pizza and Subs to pickup pizzas for campaign volunteers at the local Obama For America office on N. Bechtle Avenue in Springfield, Ohio, Tuesday evening, Oct. 23, 2012. Biden made an unannounced stop in Springfield, after a rally in Dayton with President Barack Obama. (AP Photo/Springfield News-Sun, Barbara J. Perenic)

The Election Day cliche in a close race is that "it all comes down to turnout," but it's coming down to turnout earlier this year. Because of early voting, 6.5 million Americans have already cast their ballots. But Mitt Romney and President Obama do not care about all Americans, they care about the ones in the seven swing states that will decide the election. Here's what we know about the campaigns' abilities to get their voters to the polls.

Ohio

Obama is leading Romney by 5 percentage points, according to a Time poll taken October 22 and 23. But among people who've already voted, Obama leads 60 percent to 30 percent. Among people who haven't voted yet, the candidates are tied.

At The National Review, Josh Jordan suggests early voting is skewing the poll numbers in Ohio, because the polls show more people saying they've already voted than public records show. His theory is that poll respondents are lying to pollsters to say they've already voted, and those people are more likely to say they voted for Obama, and that's throwing off the pollsters' analysis of who is really likely to vote. But The Atlantic's Molly Ball reports that in Ohio early voting, more votes have been cast in precincts that Obama won in 2008 than in ones McCain won.

What about those who haven't voted yet? Obama has 131 field offices in Ohio, while Romney has 40. Obama also has "staging locations," which are operated out of volunteers' homes. The advantage is those volunteers know their neighborhoods well. While Obama has a large get-out-the-vote operation with a ton of field offices, Romney doesn't have one at all, Ball reports. Romney has outsourced its ground game to the Republican National Committee. That way, the RNC was able to build up its turnout efforts while Romney was still fighting the primary in March.

Ohio remains "the big nut to crack," a Romney aide told The New York Times' Jeff Zeleny and Ashley Parker. Romney political director RIch Beeson tells Politico's Mike Allen that the Romney campaign has "been focusing on low-propensity [sporadic] voters, so the bulk of our votes sitting out there being high-propensity [reliable] voters. We're not going to have to worry about pushing them hard, but I just want to make sure that we can turn them out." Beeson says Republicans don't vote early because many of them are rural, and others like the social aspet of voting on Election Day.

Nevada

Here's one state where it might not be an advantage for the RNC to handle Romney's get-out-the-vote effort. The Nevada Republican Party was taken over by Ron Paul supporters, and the Romney campaign has had to create a shadow party in the state called Team Nevada. There are 90,000 more registered Democrats in Nevada than registered Republicans; in 2008, Democrats had a smaller 60,000 voter advantage, The New York Times' Adam Nagourney reports. Obama benefits from Senate Majority Leader Harry Reid's organization in the state, which "is widely praised — even by Republicans — as one of the most effective voter-organizing and money-raising political organizations."

To deal with the Ron Paul-related problems, the Romney campaign has bussed in volunteers from Southern California and Utah to contact voters in Nevada. The Atlantic reports that 1,485 more Nevada Republicans have voted by mail or in person than Democrats. In 2008, by the same date, Democrats had a 16,360-voter advantage. On the other hand, more Democrats have requested absentee ballots -- 8,230 more -- while Republicans had the absentee advantage four years ago.

North Carolina

More voters are voting early this year than in 2008, Charlotte Business Journal reports. About 817,000 people voted as of Wednesday evening, significantly more than the 647,000 who'd voted by this date in 2008. There are almost 800,000 more registered Democrats in North Carolina than Republicans as of last week.

Romney's campaign has said it's confident it will win the state. The polls have shown him ahead for a couple weeks, and according to the right-leaning poll Rasmussen, 17 percent of Democrats intend to vote for Romney, while only 4 percent of Republicans intend to vote for Obama.

Colorado

There were 7,243 more registered Republicans in Colorado as of last week. But even Republicans say Obama's ground game is good, Ball reports:

In Colorado, one top GOP consultant who has worked on presidential campaigns told me he mentally added 2 to 4 points to Obama's polls in the state based on superior organization.